Allowing unprivileged users to read /proc/slabinfo represents a securityrisk, since revealing details of slab allocations can expose informationthat is useful when exploiting kernel heap corruption issues. This isevidenced by observing that nearly all recent public exploits for heapissues rely on feedback from /proc/slabinfo to manipulate heap layoutinto an exploitable state.

Changing the permissions on this file to 0400 by default will make heapcorruption issues more difficult to exploit. Ordinary usage should notrequire unprivileged users to debug the running kernel; if this abilityis required, an admin can always chmod the file appropriately.